diff options
Diffstat (limited to 'src/include')
| -rw-r--r-- | src/include/access/heapam.h | 2 | ||||
| -rw-r--r-- | src/include/storage/bufmgr.h | 36 | ||||
| -rw-r--r-- | src/include/utils/old_snapshot.h | 75 | ||||
| -rw-r--r-- | src/include/utils/snapmgr.h | 49 |
4 files changed, 0 insertions, 162 deletions
diff --git a/src/include/access/heapam.h b/src/include/access/heapam.h index faf50265191..6598c4d7d8b 100644 --- a/src/include/access/heapam.h +++ b/src/include/access/heapam.h @@ -286,8 +286,6 @@ struct GlobalVisState; extern void heap_page_prune_opt(Relation relation, Buffer buffer); extern int heap_page_prune(Relation relation, Buffer buffer, struct GlobalVisState *vistest, - TransactionId old_snap_xmin, - TimestampTz old_snap_ts, int *nnewlpdead, OffsetNumber *off_loc); extern void heap_page_prune_execute(Buffer buffer, diff --git a/src/include/storage/bufmgr.h b/src/include/storage/bufmgr.h index b379c76e273..d89021f9187 100644 --- a/src/include/storage/bufmgr.h +++ b/src/include/storage/bufmgr.h @@ -250,8 +250,6 @@ extern void AbortBufferIO(Buffer buffer); extern bool BgBufferSync(struct WritebackContext *wb_context); -extern void TestForOldSnapshot_impl(Snapshot snapshot, Relation relation); - /* in buf_init.c */ extern void InitBufferPool(void); extern Size BufferShmemSize(void); @@ -347,9 +345,6 @@ BufferGetPageSize(Buffer buffer) /* * BufferGetPage * Returns the page associated with a buffer. - * - * When this is called as part of a scan, there may be a need for a nearby - * call to TestForOldSnapshot(). See the definition of that for details. */ static inline Page BufferGetPage(Buffer buffer) @@ -357,37 +352,6 @@ BufferGetPage(Buffer buffer) return (Page) BufferGetBlock(buffer); } -/* - * Check whether the given snapshot is too old to have safely read the given - * page from the given table. If so, throw a "snapshot too old" error. - * - * This test generally needs to be performed after every BufferGetPage() call - * that is executed as part of a scan. It is not needed for calls made for - * modifying the page (for example, to position to the right place to insert a - * new index tuple or for vacuuming). It may also be omitted where calls to - * lower-level functions will have already performed the test. - * - * Note that a NULL snapshot argument is allowed and causes a fast return - * without error; this is to support call sites which can be called from - * either scans or index modification areas. - * - * For best performance, keep the tests that are fastest and/or most likely to - * exclude a page from old snapshot testing near the front. - */ -static inline void -TestForOldSnapshot(Snapshot snapshot, Relation relation, Page page) -{ - Assert(relation != NULL); - - if (old_snapshot_threshold >= 0 - && (snapshot) != NULL - && ((snapshot)->snapshot_type == SNAPSHOT_MVCC - || (snapshot)->snapshot_type == SNAPSHOT_TOAST) - && !XLogRecPtrIsInvalid((snapshot)->lsn) - && PageGetLSN(page) > (snapshot)->lsn) - TestForOldSnapshot_impl(snapshot, relation); -} - #endif /* FRONTEND */ #endif /* BUFMGR_H */ diff --git a/src/include/utils/old_snapshot.h b/src/include/utils/old_snapshot.h deleted file mode 100644 index f1978a28e1c..00000000000 --- a/src/include/utils/old_snapshot.h +++ /dev/null @@ -1,75 +0,0 @@ -/*------------------------------------------------------------------------- - * - * old_snapshot.h - * Data structures for 'snapshot too old' - * - * Portions Copyright (c) 1996-2023, PostgreSQL Global Development Group - * Portions Copyright (c) 1994, Regents of the University of California - * - * IDENTIFICATION - * src/include/utils/old_snapshot.h - * - *------------------------------------------------------------------------- - */ - -#ifndef OLD_SNAPSHOT_H -#define OLD_SNAPSHOT_H - -#include "datatype/timestamp.h" -#include "storage/s_lock.h" - -/* - * Structure for dealing with old_snapshot_threshold implementation. - */ -typedef struct OldSnapshotControlData -{ - /* - * Variables for old snapshot handling are shared among processes and are - * only allowed to move forward. - */ - slock_t mutex_current; /* protect current_timestamp */ - TimestampTz current_timestamp; /* latest snapshot timestamp */ - slock_t mutex_latest_xmin; /* protect latest_xmin and next_map_update */ - TransactionId latest_xmin; /* latest snapshot xmin */ - TimestampTz next_map_update; /* latest snapshot valid up to */ - slock_t mutex_threshold; /* protect threshold fields */ - TimestampTz threshold_timestamp; /* earlier snapshot is old */ - TransactionId threshold_xid; /* earlier xid may be gone */ - - /* - * Keep one xid per minute for old snapshot error handling. - * - * Use a circular buffer with a head offset, a count of entries currently - * used, and a timestamp corresponding to the xid at the head offset. A - * count_used value of zero means that there are no times stored; a - * count_used value of OLD_SNAPSHOT_TIME_MAP_ENTRIES means that the buffer - * is full and the head must be advanced to add new entries. Use - * timestamps aligned to minute boundaries, since that seems less - * surprising than aligning based on the first usage timestamp. The - * latest bucket is effectively stored within latest_xmin. The circular - * buffer is updated when we get a new xmin value that doesn't fall into - * the same interval. - * - * It is OK if the xid for a given time slot is from earlier than - * calculated by adding the number of minutes corresponding to the - * (possibly wrapped) distance from the head offset to the time of the - * head entry, since that just results in the vacuuming of old tuples - * being slightly less aggressive. It would not be OK for it to be off in - * the other direction, since it might result in vacuuming tuples that are - * still expected to be there. - * - * Use of an SLRU was considered but not chosen because it is more - * heavyweight than is needed for this, and would probably not be any less - * code to implement. - * - * Persistence is not needed. - */ - int head_offset; /* subscript of oldest tracked time */ - TimestampTz head_timestamp; /* time corresponding to head xid */ - int count_used; /* how many slots are in use */ - TransactionId xid_by_minute[FLEXIBLE_ARRAY_MEMBER]; -} OldSnapshotControlData; - -extern PGDLLIMPORT volatile OldSnapshotControlData *oldSnapshotControl; - -#endif diff --git a/src/include/utils/snapmgr.h b/src/include/utils/snapmgr.h index 980d37a1947..4dc94e7ec98 100644 --- a/src/include/utils/snapmgr.h +++ b/src/include/utils/snapmgr.h @@ -19,40 +19,6 @@ #include "utils/snapshot.h" -/* - * The structure used to map times to TransactionId values for the "snapshot - * too old" feature must have a few entries at the tail to hold old values; - * otherwise the lookup will often fail and the expected early pruning or - * vacuum will not usually occur. It is best if this padding is for a number - * of minutes greater than a thread would normally be stalled, but it's OK if - * early vacuum opportunities are occasionally missed, so there's no need to - * use an extreme value or get too fancy. 10 minutes seems plenty. - */ -#define OLD_SNAPSHOT_PADDING_ENTRIES 10 -#define OLD_SNAPSHOT_TIME_MAP_ENTRIES (old_snapshot_threshold + OLD_SNAPSHOT_PADDING_ENTRIES) - -/* - * Common definition of relation properties that allow early pruning/vacuuming - * when old_snapshot_threshold >= 0. - */ -#define RelationAllowsEarlyPruning(rel) \ -( \ - RelationIsPermanent(rel) && !IsCatalogRelation(rel) \ - && !RelationIsAccessibleInLogicalDecoding(rel) \ -) - -#define EarlyPruningEnabled(rel) (old_snapshot_threshold >= 0 && RelationAllowsEarlyPruning(rel)) - -/* GUC variables */ -extern PGDLLIMPORT int old_snapshot_threshold; - - -extern Size SnapMgrShmemSize(void); -extern void SnapMgrInit(void); -extern TimestampTz GetSnapshotCurrentTimestamp(void); -extern TimestampTz GetOldSnapshotThresholdTimestamp(void); -extern void SnapshotTooOldMagicForTest(void); - extern PGDLLIMPORT bool FirstSnapshotSet; extern PGDLLIMPORT TransactionId TransactionXmin; @@ -97,14 +63,6 @@ extern PGDLLIMPORT SnapshotData CatalogSnapshotData; ((snapshot)->snapshot_type == SNAPSHOT_MVCC || \ (snapshot)->snapshot_type == SNAPSHOT_HISTORIC_MVCC) -#ifndef FRONTEND -static inline bool -OldSnapshotThresholdActive(void) -{ - return old_snapshot_threshold >= 0; -} -#endif - extern Snapshot GetTransactionSnapshot(void); extern Snapshot GetLatestSnapshot(void); extern void SnapshotSetCommandId(CommandId curcid); @@ -138,13 +96,6 @@ extern void DeleteAllExportedSnapshotFiles(void); extern void WaitForOlderSnapshots(TransactionId limitXmin, bool progress); extern bool ThereAreNoPriorRegisteredSnapshots(void); extern bool HaveRegisteredOrActiveSnapshot(void); -extern bool TransactionIdLimitedForOldSnapshots(TransactionId recentXmin, - Relation relation, - TransactionId *limit_xid, - TimestampTz *limit_ts); -extern void SetOldSnapshotThresholdTimestamp(TimestampTz ts, TransactionId xlimit); -extern void MaintainOldSnapshotTimeMapping(TimestampTz whenTaken, - TransactionId xmin); extern char *ExportSnapshot(Snapshot snapshot); |